275/50R20 vs 285/45R21
285/45R21 is 7.0 mm taller than 275/50R20 in overall diameter (+0.9%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 285/45R21 fitted, the speedometer reads 100 km/h when you are doing 100.9 km/h.
Dimensions side by side
| 275/50R20 | 285/45R21 | |
|---|---|---|
| Overall diameter | 783 mm (30.8″) | 790 mm (31.1″) |
| Section width | 275 mm | 285 mm |
| Sidewall height | 138 mm | 128 mm |
| Rim | 20″ | 21″ |
| Revolutions per km | 407 | 403 |
| In stock | 33 tires from $183.00 | 23 tires from $400.00 |
What changes
- Overall diameter: 285/45R21 is 7.0 mm taller (+0.9%).
- Speedometer: reads 100 km/h at an actual 100.9 km/h with 285/45R21.
- 285/45R21 is 10 mm wider, so check clearance and the recommended rim width.
- Wheel size changes from 20″ to 21″: you need wheels in the new size.
- Choose a load index at least as high as the one on your door placard.
Vehicles that came with both sizes
Vehicles that use 275/50R20
Vehicles that use 285/45R21
See every alternate size for 275/50R20
Frequently asked questions
Can I use 285/45R21 instead of 275/50R20?
Usually, yes: 285/45R21 is within 3% of the overall diameter of 275/50R20 (+0.9%). Use wheels of the right size and width, match or exceed the original load index, and check clearance at full steering lock.
How much does the speedometer change between 275/50R20 and 285/45R21?
With 285/45R21 instead of 275/50R20, the speedometer shows 100 km/h when you are actually doing 100.9 km/h.
Which vehicles came with both 275/50R20 and 285/45R21?
Both sizes were original equipment, on different trims or packages, on the 2019–2023 Mercedes-Benz G63, 2019–2021 Audi Q8, 2016–2018, 2020 Bentley Bentayga.